Universal dressing attachment for grinding machines



A. L. WILDER Aug. 13, 1935.

UNIVERSAL DRESSING ATTACHMENT FOR GRINDING MACHINES Fild Feb. 3, 19s; 2 Sheets-Sheet 1 INVEIITDH Aug. 13, 1935.

A. L. WILDER UNIVERSAL DRESSING ATTACHMENT FOR GRINDING MACHINES Filed Feb. 3, 1933 2 Sheets-Sheet 2 aw r 8% ATT NE) Patented Aug. 13, 1935 UNITED STATES PATENT OFFICE UNIVERSAL DRESSING ATTACHMENT FOR GRINDING MACHINES Arthur L. Wilder, Wethersfield, Conn., assignor to Pratt & Whitney Company, Hartford, Conn., a corporation of New Jersey Application February 3, 1933, Serial No. 655,114

' 6 Claims.

| An object of the present invention is to facili tate truing or dressing of the opposite conical work engaging surfaces of an abrasive wheel, which may be conveniently operated by a single movement of a slide to simultaneously and accurately dress these surfaces.

A further object of the invention is to provide a dressing attachment particularly designed for thread grinding machines which will permit the sides of the wheel being dressed being given any predetermined contour, a template having a contour corresponding exactly to the desired wheel contour on each side being mounted upon a portion of the dressing attachment.

And finally it is an object of the present in vention to provide a dressing attachment which may be adjusted over a wide variation in wheel diameters and which may be conveniently mounted upon and permanently retained in position adjacent the abrasive wheel to be trued.

One feature which enables me to accomplish the above named objects is that the dressing tool carrying members are pivotally mounted on a slide by parallel links of'equal length so that the member carrying the dressing tools may be moved to various positions, all of which are parallel to each other.

And a further feature which is advantageous is that templates for the members may be 'removably mounted upon the support for the dressing attachment in position to be contacted with by followers preferably located respectively upon the under side of the members carrying, the dressing tools.

With the above and other objects in view my invention includes the features of construction and operation set forth in the following specification and illustrated in the accompanying drawings.

In the accompanying drawings annexed hereto and forming a part of this specification I have shown my invention embodied in a dressing attachment for dressing similar opposite conical surfaces of a beveled abrasive wheel for thread grinders but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a front elevation of the complete attachment shown apart from the machine upon which it may be mounted and showing the extreme positions assumed by the dressing tools.

Fig. 2 is a transverse sectional view taken upon the broken line 2-2 of Fig. 1.

In the above mentioned drawings I have shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims other; fifth, templates on the support preferably adapted for ready removal and adapted to be adjusted to different positions; and sixth, followers on the dressing tool carrying members adapted to contact respectively with edges of their templates.

Referring more in detail to the figures of the drawings, I provide a support l0 mounted upon an extended portion of the base ll of the machine so that it may be adjusted toward and from a wheel l2 to be trued. Forithis purpose the support l0 may be mounted in -a guideway and moved toward and from the wheel by means of a screw [3 rotatably mounted in a portion of the base of the machine and engaging a nut in aportion of the support I0. For convenience in setting the support In and for adjusting the position of the dressing tools during the wearing away and consequent reduction in diameter of the wheel I2, I provide a micrometer dial l4 which may be clamped in any rotative position to the screw I3. By rotating the screw 13 as by means of the hand wheel l5 at its upper end, the position of the support In may be varied to position the attachment properly with respect to the-surfaces of the wheel l2 being dressed.

Adjustably mounted upon the front face of the support In is a slide l6 movable directly toward and'from the surfaces of the wheel I2 beupon each of the dresser bars 21.

ing dressed and preferably movable by manual means. As shown clearly in Fig. 2, a rack i1 is secured within the front surface of the support II) which is in mesh with a pinion l8 rotatably mounted in the slide it. .This pinion or gear 16 is, in turn, in mesh with a worm E9 on the inner end of a forwardly extending shaft 20. By means of a hand wheel 2i on the outer or forward end of this shaft 20 the worm l9 and gear it? may be rotated. As the gear i8 is in mesh with the rack 11 fixed to the support in, the slide i6 will be raised or lowered. In order to counterweight these parts a chain 22 is attached to an upper portion of the slide l6 and passes over a wheel 23 fixed in the base or frame H of the machine and extends in an oblique direction to the rear of the machine where a suitable counterweight may be mounted.

Secured in fixed position to the front face of the slide i6 is a member .25 in which are supported or partially supported the pivot joints 26 for the tool carrying members, 21. These members 21 are as shown in Fig. 1, short bars with their lower end obliquely disposed and within which may be suitably mounted a-dressing tool 28. In the form of the invention shown, these dressing tools 28 take the form of diamonds inserted in the forward end of small rods 29 retained within the bars 21 by a sleeve threaded therein. As the type of dressing tool 28 and its mounting 29 and adjustment within the bar 21 form no part of the present invention, it is not thought necessary that these parts require further description other than to state that the position of the diamonds in the two bars 21 is symmetrically disposed within the attachment and in retracted position may contact or come in close proximity to each other.

The bars 21 carrying the dressing tools 28 are connected to the slide I 6 by means of short parallel links so, a pair of these links so being used These links 30 are of equal length and each link is pivoted at one end to a part of the slide I6 and at its 01)- posite end to a dresser bar 21. From the above description it will be seen that the dresser bars 21 may be moved about with respect to the slide [6, each position of whichwill be parallel to any other position. Preferably and as shown, the lower pivot joints 26 between the slide it and the links 30 for the two dresser tool carrying members 21 may be upon the same axis.

As shown in Fig. 2, the connections between the bars 21 and the links 30 and between the links and the slide ii are anti-friction bearings,

the bars 21 beingdisposed symmetrically on opposite sides of the center line of the slide it so that each may be used upon one side only of the bevel surface'of the wheel to be dressed.

Mounted on the support it are templates 32 in the form of short bars, one edge of each of which is carefully finished to the desired contour, those shown in the present embodiment being straight lines. These templates 32 are mounted upon the front face .of the support in opposed positions, one for each bar 21, the slide I6 being cut away to permit movement of the slide and attached'parts toward and from the wheel l2. On the under side of each of thebars 21 is a follower 33 having an angular end hearing against the finished edge of the template 39. It will be seen from the above description that by moving the slide it downward by means of bar 21 so that the dressing tool 28 will move in a path identical to that of its template 30. Spring means 34 are employed to normally retain the bars in position so that their riders will engage the surfaces of the template.

It will be understood that any form of template 32 may be used to cut the correct conical or predetermined bevel surface on the wheel l2..

Normally, these templates 32 will be substantially straight lines modified in certain instances to cut slight curves. Whatever outline is used upon the template 32 the path of movement of the dressing tool 28 and shape produced on the wheel will correspond. It is not necessary for the two dressing attachments on opposite sides of the wheel l2 to move in exactly the same path, different templates 32 being usable if desired on the two sides,according as the wheel l2 may be adapted for grinding special threads. v

WhatIclaimis:

1. A dressing attachment for grinding machines comprising in combination, a support adapted to be mounted adjacent the abrasive wheel to be 2. A dressing attachment for grinding machines comprising in combination, a support adapted to be mounted adjacent the abrasive wheel to be.

dressed, a slide on said support movable'toward and from the wheel, a memberhaving a dressing tool thereon, a pair of parallel linlm of equal length pivotally connected to said slide and member whereby said member may be movable to different parallel positions, a template on said support, and a follower on said member engaging said template whereby said dressing tool may be guided in a predetermined path over a surface of said wheel.

3. A dressing attachment for grinding machines comprising in combination, a support adapted to be mounted adjacent the abrasive wheel to be dressed, a slide on said support movable toward and from the wheel, means to adjust said support to predetermined positions adjacent said wheel. means to move said slide on said support, members having dressing tools thereon pivotally connected to said slide for movement to difierent parallel positions, templates on said support, and followers on said members engaging said templates whereby movement of said slide will simultaneously traverse said tools over surfaces of the wheel in paths corresponding to said templates.

4. A dressing attachment for grinding machines comprising in combination, a support adapted to be mounted adjacent the abrasive wheel to be dressed, a slideon said support movable toward and from the wheel, a member'having a dressing tool thereon connected to said slide for movement to parallel positions, a template on said support, a follower on said member engaging said template whereby movement of said slide will traverse said tool over a surface of the wheel in a path corresponding precisely to that of the template,

and means to adjust said support and parts mounted thereon predetermined distances toward said wheel.

5. A dressing attachment for grinding machines comprising in combination, a support adapted to be adjustably mounted adjacent the abrasive wheel'to be dressed, a slide on said support movable toward and' from the wheel, members having dressing tools upon their ends and connected to said slide for movement to parallel positions,-

paths similar to those of the templates.

' 6. A dressing attachment for grinding machines I comprising in combination, a support adapted to be mounted for adjustment adjacent the abrasive wheel 'to-be dressed, a slide on-said support movable toward and from the wheel, members having dressing tools upon their ends connected to said slide for movement to difierent parallel positions,

templates on said support, followers on said members, means holding said followers in contact respectively with their templates whereby movement of said slide will traverse said tools over surfaces of the wheel'in a path similar to those 1 respectively of said templates.

ARTHUR L. WILDER. 

